# Closed shell structure & intrinsic molecular (electric) dipole moment

Does the closed shell structure of a molecule imply that it has an intrinsic (electric) molecular dipole moment? If so, why is that?

I came across this in paper [1], which seems to suggest that this is the case on page 6 (top left-hand corner):

While both inorganic thin ﬁlms and organic monolayers alter the charge rearrangements between the two contacting bulks, organic molecules add their own, “intrinsic” dipole caused by the closed shell nature of molecules. Thus, electron-withdrawing (e.g., halogens, $\ce{CN}$, and $\ce{NO2}$) or -donating groups (e.g., $\ce{OMe}$ and $\ce{NH2}$) can induce huge electric ﬁelds within a single molecule. Adsorbing molecules so that they will be at solid interfaces can in principle aﬀect, and thus modify, any of the interfacial mechanisms: interface traps ..., molecular dipoles ..., and charge rearrangement ...

### Bibiliography

1. Vilan, A.; Cahen, D. Chemical Reviews 2017, 117 (5), 4624–4666. DOI 10.1021/acs.chemrev.6b00746.